Orienting and perforating methods and apparatus



Dec. 27, 1966 M. P. LEBOURG ORIENTING AND PERFORATING METHODS ANDAPPARATUS 5 SheetsSheet 1 Filed Feb. 24, 1959 2468mM2468 3 5 7 9 l 3 5 79 Mdu/vce P Z @600 INVENTOR. 7

BYQ Al/ ATTORNEY Dec. 27, 1966 P. LEBOURG 3,294,163

ORIENTING AND PERFORATING METHODS AND APPARATUS Filed Feb. 24, 1959 5Sheets-Sheet 2 52- Jlfl 5 Maur/ce P A 9600/ INVENTOR.

ATTORNEY Dgc. 27, 1966 M P. LEBOURG ORIENTING AND PERFORATING METHODSAND APPARATUS Filed Feb. 24, 1959 5 Sheets-Sheet 5 MOU/Vf f labour?INVENTOR.

* wwww ATTORNEY Dec. 27, 1966 M. LEBQURG 3,294,163

ORIENTING AND PERFORATING METHODS AND APPARATUS Filed Feb. 24, 1959 5Sheets-Sheet 4 MOM/7C6 F. L eboury INVENTOR.

ATTORNEY Dec. 27, 1966 M. P. LEBOURG 3,294,163

ORIENTING AND PERFORATING METHODS AND APPARATUS Filed Feb. 24, 1959 5Sheets-Sheet 5 3 i2 /Z //0 L [NTENJ/T) /flr? INDEXED POJ/T/O/VS Moor/ref. leou/y INVENTOR.

3,294,163 ORIENTING AND PERFORATING METHODS AND APPARATUS Maurice P.Lebourg, Houston, Tex., assignor to Schlumberger Well SurveyingCorporation, Houston, Tex., a

corporation of Texas Filed Feb. 24, 1959, Ser. No. 795,099 4 Claims.(Cl. 1664) This invention relates to perforating sistems and moreparticularly to methods and apparatus for orienting the direction offiring of a perforating apparatus in one of a plurality of tubingstrings in a borehole.

Multiple well completion techniques are concerned with the problem ofobtaining independent production from a plurality of producing zonesthrough a single borehole where the zones are spaced vertically from oneanother. In one technique of completion, after the borehole has beendrilled and the casing set, each production zone is independentlyperforated and packed off, starting with the lowermost zone and endingwith the zone nearest the surface of the earth. Tubing strings are thenindividually introduced through the packers to the various productionzones, starting with a tubing string extending to the lowermost zone,another tubing string to the next higher zone and so forth until eachproducing zone is separated from one another by packers and opens intothe lower end of a string of tubing.

In another technique of multiple well completion, after the borehole hasbeen drilled, the tubing strings are positioned with their respectivelower ends at each of the production zones involved and the entireborehole filled with cament so that each tubing string eifectivelyserves as a casing. Selective perforation of the various productionzones may then be accomplished by apparatus disclosed in a copendingapplication of the applicants S.N. 760,138, filed September 10, 1958,now abandoned in favor of a continuation-in-part application S.N.816,993, filed May 29, 1959, now Patent No. 3,168,141. Brieflydescribed, in aforesaid application, a perforating apparatus is providedwith an orienting means arranged to cooperate and align with a speciallocating collar inserted in a preselected position in the tubing string.The perforating or firing axes (or axis) of the perforating apparatusare located with respect to the orienting means and collar so as toavoid perforation of adjacent, coextending tubing strings. While thisapparatus is highly successful and satisfactory, it does require thatthe locating collar be positioned in the tubing string at the time thestring of tubing goes into the well.

Therefore, it will be appreciated that in either of the above instances,an orienting system which may orient a perforating apparatus without theneed of mechanical devices in the tubing string has a more universalappeal.

It is accordingly an object of the present invention to provide a newand improved method of orienting the firing axis of a perforatingapparatus in awell bore.

Another object of the present invention is to provide a new and improvedorienting means for use with perforating apparatus.

It is a further object of the present invention to provide a new andimproved orienting means to orient the firing axes of a perforatingapparatus.

Another object of the present invention is to provide a new and improvedorienting means for use with perforating apparatus in a multiple wellcompletion wherein the perforating apparatus in one string of tubing hasa zone in which perforations are not produced, the orienting meanspermitting orientation of the zone relative to other coextending stringsof tubing to prevent perforation thereof.

These and other objects of the present invention are achieved bylowering, into one of a plurality of tubing United States Patent Officewith particularity in the appended claims.

10 of FIG. 9;

3,294,163 Patented Dec. 27, 1966 strings in a well, a perforator havingat least one laterally extending zone in which perforations are notproduced. Energy-emitting and detecting devices positioned atcorresponding levels in the respective tubing strings provide signalsrepresenting energy transmitted between the devices in the respectivetubing strings. One of the devices is positioned in the first tubingstring and includes means rotatable in a predetermined relation to theperforator. Thus the detected signals are varied in accordance with therelative orientation of the rotatable means in relation 'to the other ofsaid devices whereby the perforator may be oriented in accordance withthe signals selectively to perforate only the first tubing string.

' In one embodiment of the invention, in a first tubing, a transversebeam of radiation from a radioactive source is oriented in apredetermined relatlonship to a perforator zone on a perforator, thezone being one in which perforations are not produced, while in anothertubing, :1 radiation detector is provided. The beam of radiation and theaforesaid perforation zone are rotated relative to the first tubingstring and the intensity of radiation received by the detector providesa direct indication of the relative angular position of the beam inrelation to the detector thereby permitting orientation of theperforator.

In another embodiment of the present invention, in a first tubing, asource of radiation from a radioactive source is provided. In acoextending string of tubing, a radiation detector is encased by arotatable isolation shield, the shield having an opening to admitradiation to the detector.

'The aforesaid opening is oriented in a predetermined rela- 'tion to theperforator zone of a perforator in which zone perforations are notproduced. Rotation of the shield and opening relative to the othertubing string varies the intensity of radiation received by the detectorand thereby provides a direct indication of the relative angularposition of the opening. Thus, the aforesaid perforator zone may beoriented.

The novel features of the present invention are set forth The presentinvention, both as to its organization and manner of operation togetherwith further objects and advantages thereof, may best be understood byway of illustration and example of certain embodiments when taken inconjunction with the accompanying drawings in which:

FIG. 1 is an elevational view of an energy-emitting means together witha perforating apparatus in one string of tubing and an energy-receivingmeans in another string of tubing, the tubing being cemented in aborehole;

FIG. 2 is a cross-sectional view taken along line 22 of FIG. 1;

FIG. 3 is a view in longitudinal cross section of the energy-emittingdevice taken along line 33 of FIG. 1 and drawn to a larger scale;

FIG. 4 is a horizontal cross-sectional view taken along line 44 of FIG.3;

FIG. 5 is a horizontal cross-sectional view taken along line 5--5 ofFIG. 3;

FIG. 6 is a view illustrated in a plane of the indexing slot system onthe periphery of the indexing means;

FIG. 7 is a perspective vieW of a portion of the indexing slot systemshown in FIG. 6;

FIG. 8 is a graph or log of the response of the energydetecting deviceas the energy-emitter and perforating apparatus of FIG. 1 is rotated;

FIG. 9 is an elevational view of a modified arrangement of the presentinvention wherein the energy-detecting device together with aperforating apparatus are disposed in one string of tubing, theenergy-emitting device being in another string of tubing and the tubingstring cemented in the borehole;

FIG. 10 is a view in cross section taken alon line 10- FIG. is a graphor log of the response of the devices:

shown in the embodiment of FIG. 14.

Referring now to the drawings, in FIG. 1, a borehole extends throughearth formations 21 and 22, the formation 22 being the one selected forperforation. Tubings or conduits 23, 23' extend coextensively of oneanother and are cemented in borehole 20, the tubing 23 terminatingshortly below the formation 22 and the tubing 23 extending downwardlythrough another formation of interest (not shown). It will beunderstood, of course, that it is desired to produce independently fromseparate formations at different levels and that, while only two tubingstrings are illustrated, three or more tubing stringsv may be in theborehole in accordance with the teachings of the present invention aswill hereinafter become more apparent.

A tool 24 is suspended in the tubing string 23 adjacent to formation 22by means of an armored electrical cable 25. Cable 25 is spooled on awinch (not shown) which, in a customary manner, serves to raise andlower the tool through the tubing. Tool 24 includes a conventional cablehead attachment and collar locator 27, a radiationemitting device 28, anindexing mandrel 29 and perforating apparatus 30 which areinterconnected to one another to form a unitary assembly. Indexingmandrel 29 is slidably received within the central bore 31 (see FIG. 3)of an indexing centralizer 32 for relative rotation therebetween and forlimited longitudinal movement. Centralizer 32 is provided with aplurality of outwardly extending spring arms 33 which frictionallyengage with the inner wall of tubing 23 in a conventional manner. Arms33 are attached by their ends to the centralizer in a conventionalmanner.

Perforating apparatus 30 may be any one of the presently knowncommercial types which is adapted to pass through tubing. For example,shaped charge perforating means 34, 34' may be disposed in a tubularhousing 35 and suitably interconnected in a well-known manner either forsuccessive or simultaneous detonation. The firing axes 36, 37 (indicatedby the dotted line arrows in FIG. 2) of the perforating means 34, 34',that is, the

, axes along which the perforating jets travel, are preferably phased180 from one another and lie in a longitudinal plane which intersectsthe central axis 38 of the tool assembly. With this arrangement therewill be blind zones A and B on either side of the perforating axes 36,

37 in which perforations are not produced, the zones A and B extendinglongitudinally of the perforator 30. Obviously the perforating means maybe arranged to fire only 'in one direction or can be aligned relative toone another in any preselected manner in harmony with the principles ofthe invention which will hereinafter become more apparent.

The radiation-emitting device 28 has a source of radioactivity 39 suchas radium which emits gamma rays, the

gamma rays being collimated in a radial beam as shown by the arrow 40 inFIG. 2. If the beam of radiation or energy 40 is arranged perpendicularto firing axes 36, 37 then when the beam is directly towards or awayfrom tubing 23', the firing axes 36, 37 will clearlyavoid perforation ofthe tubing 23.

To obtain an indication of the intensity of the beam of energy 40, anenergy-receiving device 41 is suspended in tubing 23' at a levelgenerally corresponding to the depth of the energy-emitting device 28 bymeans of a conventional spooling winch 42 and an armored electricalcable 43. Energy-receiving means 41 is, of course, complementary to theenergy-emitting means 28 and, for example, a Geiger-Mueller counter orscintillation counter may be used to detect the gamma rays and providean electrical signal in response to the intensity of the rays.

The signal provided by the receiving device 41 is received by a recorder44, at the surface of the earth through the electrical cable 43.Recorder 44 is adapted to record variations in the intensity ofradiation received by receiving device 41 for various angular positionsof the beam of energy 40 with respect to tubing string 23 to produce anexemplary curve 47 (see FIG. 8) from which orientation of the beam 40can be determined. Of course, a meter or other suitable indicatingdevice may be employed if so desired.

Referring now to FIG. 3, the energy-emitting device 28 includes atubular housing 50 connected at its upper end by screw means 51 and acoupling cylinder 52 to the lower end portion of the casing collarlocator 27. The lower end of housing 50 threadedly receives the upperend portion of the cylindrical indexing mandrel 29 at 54. Fluid seals55, 56 and 57 such as 0 rings for the abovedescribed connections providea fluid-tight interior. Within the housing 50, a tubular spring fingerclamping member 58 threadedly secured at 59 to the lower end of coupling52 firmly secures a cylinder member 60 in a fixed longitudinal positionin the housing 50. Cylinder member 60 and coupling 52 are prevented fromrelative rotation by means of a locking pin connection at 61.

Disposed in a longitudinally extending blind bore 62 in the upper end ofthe cylinder member 60 is the source of radioactivity 39, for example,radium, which is sealed in the bore by a plug member 64. The cylindermember 60 and plug member 64 are constructed of radioactivity absorbingmaterial, for example, a heavy metal such as lead. To collimate thedirected beam of energy 40 in a transverse direction relative to thehousing 50, a passageway 65 is provided which extends between theradioactivity source 39 and the outer periphery of the cylinder member60. The passage 65 is more accurately defined by the frustrum of a.pyramid having an apex located on the center line of the radioactivitysource 39 and a rectangular base at the outer periphery of cylinder 60.The angle defined between the respective upper and lower surfaces 66, 67and the side surfaces 68, 69 (FIG. 4) of the passage 65 effectivelydetermines the beam width in longitudinal and transverse planes. Theside surfaces 68, 69 which determine the beam width in a transverseplane have a relative small angle (FIG. 4), for example about 15. Thetubular housing 50 is, of course, constructed of material such as steelwhich will pass the emitted radiation. A central bore 70 extends throughthe cylinders 52, 60 and mandrel 29 to provide a suitable passageway forelectrical conductors 71 of the detonating system. Conductors 71 areconnected between the perforator 30 and a source of power at the surfacein a well-known manner.

Indexing mandrel 29 is provided with a slot system 73 while centralizer32 is provided with a follower 76 extending into the slot system 73.Follower 76 is formed by a spring ring clamp 77 (see FIG. 3) received inan annular groove 78 in the upper end of centralizer 32, an opening 79in the bottom of the groove 78 permitting a follower end 76 of clamp 77to extend therethrough into slot system 73.

The indexing system hereinafter described is more completely detailed inthe copending application filed on February 24, 1959, Serial No.294,877, now Patent No. 3,154,147, assigned to the present assignee,however, the basic details so far as an understanding of the nature ofthe device is concerned is briefly as follows: Slot system 73 includes aplurality of identically arranged rectangular slots 74 equidistantlyspaced about the periphery of the mandrel, the longitudinal slots beinginterconnected respectively by identically arranged slots 75 which arealso rectangular (see FIGS. 5-7). Each of the longitudinal slots 74extends between an upper terminal end portion 80 (FIG. 3) located abovethe lower end surface 81 of housing 50 and a lower terminal end portion82, the spacing between terminal end portions 80, 82 being approximately30 inches. Intermediate of the length of each slot 74, the upper bottomwall portion 83 of the slot is connected by an outwardly inclined bottomwall portion 84 to a raised bottom wall portion 85. Raised wall portion85 and the lower bottom wall portion 86 of the slot form a downwardlyfacing shoulder 87. Hence, as the mandrel 29 moves upwardly relative tocentralizer 32 from a lower position to an upper position, the follower76 adjacent to bottom wall portion 83 is cammed outwardly by theinclined portion 84, follows over raised portion 85 and is resilientlyreturned to its initial position in lower portion 86 upon passing overshoulder 87.

Inclined slots 75 are connected between the lower portion 86 of onelongitudinal slot below shoulder 87 and the upper portion 83 of anadjacent longitudinal slot. Each inclined slot 75 has, at its lower end,a bottom wall portion 88 which is connected by an outwardly inclinedbottom wall portion 89 to a raised bottom wall portion 90. Raised wallportion 90 opens into a sidewall of the other longitudinal slot so thata shoulder portion 91 is formed in the sidewall. Hence, as the indexingmandrel 29 is lowered relative to the centralizer 32, follower 76 willengage shoulder 87 and be transferred into the inclined slot 75 andthereupon be cammed outwardly by the inclined portion 89, follow raisedwall portion 90 and resiliently return to the upper portion 83 of alongitudinal slot upon pasisng over shoulder 91.

In operation, the tool 24 is assembled so that the firing axes 36, 37are at right angles to the beam of energy 40 so that a zone in whichperforations are not produced is in alignment with the beam of energy40. The tool 24 is then lowered through the tubing 23, the weight beingsufiicient to overcome the frictional drag of centralizer 32, to thelevel to be perforated. The energy-detecting device 41 is then loweredthrough tubing 23 to a corres onding level so that tool 24 and device 41are adjacent to one another. Assuming the tool 24 and device 41 to be inan initial position as shown in FIG. 2, the beam of energy 40 or, morespecifically, gamma rays emitted from the radiation source 63 in a beamdefined between the walls 66, 67, 68 and 69 of passage 65 are directedtowards the detector device 41 so that the intensity of radiationindicated by the recorder 44 is at maximum as shown by the point 94 oncurve 47 which corresponds to an index position #1 on the log. In thisposition follower 76 lies in the upper portion of a longitudinal groove,the downwardly facing shoulder 81 of housing so abutting the uppershoulder 95 of centralizer 32. Upon recording of point 94 of curve 47the operator raises the tool 24, e.g., approximately 26 inches so thatthe follower pin 76 now resides in the lower portion of the slot 74, thecentralizer remaining stationary due to the frictional force ofcentralizer springs 3-3. The tool 24 is then lowered a correspondingdistance of 26 inches so that follower pin 76 follows inclined slot 75to the adjacent longitudinal slot, the tool being rotated 30 due to thecamming action of the inclined slot 75 and follower pin 76. At indexposition #2 where the tool is now positioned, the intensity is recordedas a point 96 of the curve, the intensity being decreased since the beam40 has been angularly displaced relative to the detecting device 41.Continued indexing in the above-described manner is carried out untilthe intensity at twelve indexing positions has been plotted on the log.The curve 47 therefore provides an indication of the intensity of thebeam of radiation at various indexed positions, the minivmum point 97 ofthe curve indicating when the beam is pointed directly away from thedevice 41, the maximum points 94, 94a indicating when the beam ispointed 6 directly towards the device 41. Hence, the zone of theperforator in which perforations are not produced may be located withrespect to the other tubing 23' so that perforator 30 may be fired withthe perforations passing through the cement and the formations 22 butwithout perforating tubing 23'.

In the embodiment of FIG. 9, a source of radioactivity 98 is suspendedin tubing 23' while the detecting device 41 is associated withperforator 30 in the tubing 23. More specifically, the detector 41 isfixed relative to the centralizer 101 and a tubular shielding member 102having an elongated opening 103 therein is adapted to be rotatedrelative to the detecting device to obtain a selective sampling ofradiation about the entire periphery of the device 41. Hence, theradiation received by the detector device 41 may be considered as a beamof energy 104 (see FIG. 10) directed towards the device 41. As shown inFIG. 11, detector 41 is threadedly secured in a bore 105 of a tubularextension 106 of centralizer 101. Tubular extension 106 is reduced indiameter to receive the tubular shielding member 102 and bearing means107 near the upper end of member 102 rotatively secures the member 102to extension 106. The lower end of shielding member 102 is threadedlysecured to perforator 30 at 108, the upper end portion 109 of theperforator being spaced from the lower end portion 110 of extension 106to receive an indexing device 111. A fluid seal means 112 is providednear the lower end of extension 106 to fluidly seal the member 102 andextension 106 relative to one another.

Shielding member 102 and the lower portion of centralizer 101 are coatedwith a heavy metal 114 to prevent passage of radiation therethroughexcept for the rectangular opening 103 located near the upper end of themember 102. Opening 103 has a narrow width between its sidewalls 115,116 (see FIG. 10) to confine the radiation entering the opening torelatively narrowbeam width.

Positioned below detector 41 in bore 105 and separated therefrom by aspacer 117 is a solenoid coil 118. Below coil 118, a bore 120 of reduceddiameter slidably receives an indexing cylinder 121 which is connectedat its upper end to a solenoid armature 122. Cylinder 121 is resilientlybiased in a direction away from coil 118 by a spring 123. Near the lowerend of member 106, a transversely disposed pin member 124 extends intobore 120 to be received in an indexing slot system 125 in the peripheryof cylinder 121. The lower end portion of cylinder 121 which extendsbeyond end portion 110 is provided with transversely disposed pinmembers 126, 127 extending at right angles to cylinder 121. A tubularcamming member 128 secured to shielding member 102 is provided withgenerally triangular notches 129 in its upper end which form triangularfingers 130, the end portions of pin members 126, 127 being receivedwithin notches 129 and adapted to cooperate with fingers 130 (see FIG.12).

The indexing pin 124 and slot system 125 which are arranged in apredetermined relation to notches 129 and fingers 130 will now beexplained with reference to FIGS. 13A and 13B. Slot system 125 isgenerally N-shaped and comprised of longitudinal slots 125a, 125b, 1256,125d spaced 90 from each other and inclined grooves 125ab, 125bc, 1250a,125da connected between the respective upper and lower ends of thelongitudinal grooves. Each of the upper ends of the inclined slots isoffset slightly from the upper end of a longitudinal slot to form apocket 132 to insure a one-way travel of the pin 124 in the slot system125. The lower ends of the inclined slots are directly below thesucceeding longitudinal slots and are also beveled to insure the one-waytravel. Fingers 130 are six in number being spaced 60 from one anotherand arranged relative to the slot system 125 so that when indexing pin127 is disposed in pocket 132, the apex of one of the fingers islongitudinally'aligned therewith while pins 126, 127 lie in a pair ofoppositely opposed grooves 129.

In an operation of the indexing means, energization of solenoid coil 118by a suitable power supply at the surface raises the cylinder 121, theindexing pin 124 and indexing slot system 125 thereby producing relativerotation between the cylinder 121 and shielding member 106. In anexamplary cycle, when index pin 124 goes from an upper pocket 132 at A(FIG. 13A) to a lower position at B, the camming pin member 126 israised and rotated to move from a position C between the cam fingers130a, 13012 to a position D above the cam fingers 130 (FIG. 13B) and,before diseangagement with cam finger 13012 rotates the shielding member106 through an angle of 30 relative to extension 106 (held againstrotation by spring cage 48). In position D, the pin member 126 islocated above and between fingers 130b, 130a so that when the cylinder121 is lowered by the action of spring 123 upon the de-energizing ofsolenoid coil 118, the pin member 124 will be positioned in the notch129a between the cam fingers 130b, 1300. Thereafter, if the solenoidcoil 118 is again energized and de-energized, the indexing cycle abovedescribed will be repeated.

The operation of the apparatus described with respect to FIGS. 9-13 issubstantially the same as the apparatus of FIGS. 1-8. That is, once thedetecting and emitting devices 41 and 9 8 are positioned in the tubing,opening 103 which defines a beam of energy is rotated by theabovedescribed indexing means 111 and the intensity of energy receivedin recorded on the log. The beam of energy is, of course, orientedrelative to the blind zone of the perforator. At a maximum value ofintensity, the perforating axes 36, 37 are oriented so as not tointersect tubing 23' and the perforating means may be detonated.

Referring now to the embodiment shown in FIG. 14, an assembly 130 havingperforating axes 36, 37 transverse to a beam of energy 40 as abovedescribed is disposed in a tubing 131 which is to be perforated. Tubings132, 133 are coextending with tubing 131 and respectively receiveidentical detecting devices 41a, 411) which cooperate with the beam ofenergy 40 to provide an indication of the intensity of energy received.As shown in FIG. 15, devices 41a, 41b independently produce curves 134,135 respectively forming a graph of the intensity received by theindividual devices plotted against the rotational orientating of thebeam of energy which is derived similar to the log of FIG. 8. Asummation curve 136 of the curves 134, 136 indicates that at position #7the directional characteristic bisects the center line between tubings132, 133 so that perforating axes 36, 37 do not intersect the aforesaidtubings.

It should be readily apparent from the foregoing that the presentinvention sets forth novel methods of orienting an apparatus in a wellhaving a plurality of coextending tubing strings.

Moreover, novel apparatus has been provided to orient a specificapparatus in one of a plurality of tubing strings in a well boreincluding energy-emitting and receiving devices arranged for positioningat corresponding levels in respective tubing strings to provide signalsrepresenting energy transmitted between said devices in said tubingstrings.

While particular embodiments of the present invention have been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects andtherefore the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is:

1. Apparatus for perforating one of a plurality of tubing strings in awell comprising: an elongated well perforator adapted for passage in afirst tubing string and having perforating axes defining at least onezone extending longitudinally thereof in which perforations are notproduced; means to frictionally engage the walls of said first tubing;

means coupled to said friction means and said perforator for rotatingsaid perforator relative to said friction means through a plurality ofangular positions in which the perforator is disposed at the same levelin the well thereby to orient said zone relative to another of saidtubing strings; energy-emitting and receiving devices arranged to bepositioned at corresponding levels in the respective tubing stringsdiiferent from the level of the perforator to provide signalsrepresenting energy transmitted between said de= vices in said tubingstrings with one of said devices being coupled to said perforator andsaid rotating means so that said one device is at the same level in thewell at all of said angular positions of said perforator; and means toeffect a beam of energy at said one device whereby said one device andperforator may be rotated to vary the detected signals in relation tothe other of said devices to obtain a selective orientation of saidperforator Zone.

2. Apparatus for perforating one of a plurality of tubing strings in awell comprising: an elongated Well perforator adapted for passage in afirst tubing string and having perforating aXes defining at least onezone extending longitudinally there-of in which perforations are notproduced; means to frictionally engage the walls of said first tubing;means coupled to said friction means and said perforator for rotatingsaid perforator relative to said friction means through a plurality ofangular positions in which the perforator is disposed at the same levelin the well thereby to orient said zone relative to another of saidtubing strings; radiation-emitting and radiation-receiving devicesarranged to be positioned at corresponding levels in the respectivetubing strings above the level of said perforator to provide signalsrepresenting the intensity of radiation transmitted between said devicesin said tubing strings with one of said devices being coupled to saidperforator and said rotating means so that said one device is at thesame level in the well at all of said angular positions of saidperforator; and means to collimate a beam of energy with respect to saidone device whereby said one device and perforator may be rotated to varythe detected signals in relation to other of said devices to obtain arelative orientation of said perforator zone.

3. A method for orienting perforating apparatus in one of a plurality ofpipe strings in a well comprising the steps of rotating said perforatingapparatus through a plurality of angular orientations within said onepipe string, creating at the same level in the well for each of saidangular orientations of said perforating apparatus a distribution ofenergy which characterizes the angular orientation of at least a secondpipe string with respect to said one pipe string at such level,detecting said energy distribution at the same level in the well foreach of said angular orientations of said perforating apparatus toobtain a signal at the earths surface indicative of said angularorientation, and rotating said perforating apparatus in said one pipestring to a position in prescribed relation to said angular orientation.

4. A method for orienting perforating apparatus in one ofa plurality ofpipe strings in a well comprising the steps of rotating said perforatingapparatus through a plurality of angular orientations within said onepipe string, creating at the same level in said well above the locationof said perforating apparatus in said one pipe string for each of saidangular orientations of said perforating apparatus an angular variationin energy to characterize the angular orientation of at least a secondpipe string with respect to said one pipe string at such level,detecting said energy distribution at the same level above the locationof said perforating apparatus for each of said angular orientations ofthe perforating apparatus to obtain a signal at the earths surfaceindicative of said angular orientation, and rotating said perforatingapparatus in said one pipe string to a position in prescribed relationto said angular orientation.

(References on following page) 9 10 References Cited by the Examiner2,875,347 2/1959 Anderson et a1. 2501()8 2,988,068 8/ 1961 True 166-55UNITED STATES PATENTS 3,054,454 9/1962 Evans 1-66- 168 X 2/ 1939 Potts255-28 1/131; Brons 5 CHARLES E. OCONNELL, Primary Examiner. Ennis HareExwmlne 7/1955 Herzoz 25043.5 C. O. THOMAS, D. C. BLOCK, D. H. BROWN,6/1957 Abendroth 16655.5 X Assistant Examiners.

3. A METHOD FOR ORIENTING PERFORATING APPARATUS IN ONE OF A PLURALITY OFPIPE STRINGS IN A WELL COMPRISING THE STEPS OF ROTATING SAID PERFORATINGAPPARATUS THROUGH A PLURALITY OF ANGULAR ORIENTATIONS WITHIN SAID ONEPIPE STRING, CREATING AT THE SAME LEVEL IN THE WELL FOR EACH OF SAIDANGULAR ORIENTATIONS OF SAID PERFORATING APPARATUS A DISTRIBUTION OFENERGY WHICH CHARACTERIZES THE ANGULAR ORIENTATION OF AT LEAST A SECONDPIPE STRING WITH RESPECT TO SAID ONE PIPE STRING AT SUCH LEVEL,DETECTING SAID ENERGY DISTRIBUTION AT THE SAME LEVEL IN THE WELL FOREACH OF SAID ANGULAR ORIENTATIONS OF SAID PERFORATING APPARATUS TOOBTAIN A SIGNAL AT THE EARTH''S SURFACE INDICATIVE OF SAID ANGULARORIENTATION, AND ROTATING SAID PERFORATING APPARATUS IN SAID ONE PIPERSTRING TO A POSITION IN PRESCRIBED RELATION TO SAID ANGULAR ORIENTATION.